The invention relates to safety devices for mechanical equipment and, more specifically, to a motion sensing monitor that turns off certain equipment elements of a ground-traveling machine when the machine either stops or slows below a threshold speed.
Ground traveling machines are employed in a wide variety of industries and applications, most notably agriculture and earth moving. While manufacturers of these machines take great care to design and shield the machines so as to limit the likelihood of injury to operators during use of the equipment, injuries still result due to tampering with the shielding or when operators ignore the operating instructions or warnings. An effective approach to further limiting operator injuries is to provide interlocks that turn-off the accessible moving parts of the machines when the operator approaches the moving parts or leaves the operator's station. For example, riding lawn mowers frequently include switches in the operator's seat which act to stop the rotating blade when the weight of the operator is no longer on the seat.
A motion sensing monitor for ground-traveling machinery is known wherein one or more magnets are mounted on an axle that is extended across the full transverse width of the machine. As the machine travels across the ground, the magnet is rotated on the axle. A magnetic sensing device is mounted on the frame of the machine so that it senses the magnet on each pass. Monitoring circuitry calculates and displays acres covered by the machine and ground speed.